Archiv: this solar system / dieses Sonnensystem


26.04.2024 - 00:00 [ Journal of Geophysical Research: Solid Earth / onlinelibrary.wiley.com ]

Possible Eoarchean Records of the Geomagnetic Field Preserved in the Isua Supracrustal Belt, Southern West Greenland

(24 April 2024)

The preservation of a temperate climate and liquid water on early Earth depends critically upon the strength of the magnetosphere (Sterenborg et al., 2011; Tarduno et al., 2014). Recent atmospheric escape models have suggested that both weak (<10 μT) and strong (>1 mT) magnetic fields could substantially enhance atmospheric escape under present-day solar wind conditions via the polar wind or cusp escape, respectively (Gronoff et al., 2020; Gunell et al., 2018; Lundin et al., 2007). During the Archean, the Sun was rotating faster, generating a stronger stellar dynamo and therefore the solar wind was more intense than today (Vidotto, 2021). An increased solar wind strength causes greater interaction with the upper atmosphere and greater escape of ions assuming a constant level of protection from Earth‘s magnetosphere. Previous magnetohydrodynamic simulations have suggested that if Earth‘s magnetic field was half its present day strength 3.5 Ga ago, the area of the polar cap (the area containing open dipolar magnetic field lines, allowing atmospheric escape via the polar wind) could increase by up to 50% (Sterenborg et al., 2011).

25.04.2024 - 23:52 [ IFLscience.com ]

The Earth’s Magnetic Field Is At Least 3.7-Billion-Years Old, New Evidence Shows

The age of the Earth’s magnetic field remains under question in part because we don’t fully understand what causes it today. We know it is a product of movements in the molten outer core, whose high iron content turns convection currents into a dynamo, and these currents in turn are produced by the solidification of the inner core.

25.04.2024 - 23:45 [ livescience.com ]

Earth‘s magnetic field formed before the planet‘s core, study suggests

(24 April 2024)

Today, the magnetic field is driven by the churning of the liquid part of the core and the transfer of heat from the solid inner core to the convective outer core as the former cools. But researchers think the core didn‘t solidify until about a billion years ago.

14.06.2023 - 13:08 [ NASA New Horizons / Twitter ]

#OTD in 2019, @NASA‘s #NewHorizons flew by Arrokoth, the farthest object ever explored by spacecraft. Arrokoth is about about 50 AU, or 4 billion miles from the Sun. New Horizons is ~56 AU from Earth and will join Voyagers 1 & 2 in interstellar space in the 2040s.

14.06.2023 - 12:59 [ Youtube ]

5 Spacecraft Are Leaving The Solar System. What Did They See In Their Journey?

Pioneer 10: Pioneer 10 was launched in 1972 to explore the planets of the solar system. It achieved the first flyby of Mars, the first trip through the asteroid belt, and Jupiter‘s first flyby. It was the first time NASA had used nuclear energy to power its spacecraft. So, after Pioneer 10 passed Jupiter in 1973, it still had ample energy to keep going. Initially planned for 21 months, it continued to communicate with Earth for a total of 30 years.

14.06.2023 - 12:50 [ Space.com ]

What Spacecraft Will Enter Interstellar Space Next?

(January 30, 2019)

This milestone — reaching interstellar space — can be considered leaving the solar system by a certain definition. Let‘s be clear about what that entails. In 1990, the New York Times reported that Pioneer was reported to leave the solar system when it flew past Neptune‘s orbit. That‘s not what Voyager 2‘s scientists used to make their determination, however. Instead, the more recent measurements consider the crossing of the sun‘s heliopause, the theoretical boundary to its heliosphere, to be the determining factor for entering interstellar space. The heliosphere is a bubble of charged particles created by and flowing past the sun. Scientists use it to mark where interstellar space begins.

14.06.2023 - 12:47 [ ORF.at ]

Raumsonde „Pioneer 10“ 40 Jahre aus Sonnensystem heraus

Am 13. Juni 1983 durchflog „Pioneer 10“ die Umlaufbahn des Neptun und wurde so laut NASA zum ersten menschengemachten Raumschiff, das am weitestentfernten bekannten Planeten unseres Sonnensystems vorbeiflog. Neptun ist im Mittel etwa 4,5 Milliarden Kilometer von der Sonne entfernt.

Mit „Pioneer 11“ und den beiden „Voyager“-Sonden folgten später ähnliche Missionen. „Voyager 1“ überholte „Pioneer 10“ schließlich als am weitesten von der Erde entferntes menschengemachtes Objekt. Zum bisher letzten Mal schickte „Pioneer 10“ im Jänner 2003 Daten, ein Kontaktversuch im März 2006 scheiterte.

26.12.2022 - 06:31 [ Electroverse.co ]

Cold Records Shattered Across Canada, Driving Energy Usage To All-Time Highs; Extreme Freeze Sweeps U.S.; Blizzards Hit Hawaii; + Wintry Weather Traps 300 Oil Workers On North Sea Rig

(December 21, 2022)

As hinted at above, Mauna Loa began erupting on Nov 27 and stopped on Dec 13.

It was the first time it has actively erupted since 1984 (solar minimum of cycle 20) — and is a sign of the times…

Volcanic eruptions are one of the key climatic forcings driving Earth into its next bout of global cooling. They have been shown to increase in both number and explosivity during times of prolonged solar decline, which is thought to be due to an influx of cosmic rays (CRs) penetrating/exciting silica-rich magma. During solar mins the Sun’s magnetic field weakens and the outward pressure of the solar wind decreases, which allows more CRs to enter the inner solar system, including our planet’s atmosphere.

25.10.2021 - 19:22 [ arxiv.org ]

A Unified Model for the Fan Region and the North Polar Spur: A bundle of filaments in the Local Galaxy

We present a simple, unified model that can explain two of the brightest, large-scale, diffuse, polarizedradio features in the sky, the North Polar Spur (NPS) and the Fan Region, along with several otherprominent loops. We suggest that they are long, magnetized, and parallel filamentary structures thatsurround the Local arm and/or Local Bubble, in which the Sun is embedded. We show this modelis consistent with the large number of observational studies on these regions, and is able to resolvean apparent contradiction in the literature that suggests the high latitude portion of the NPS isnearby, while lower latitude portions are more distant. Understanding the contributions of this localemission is critical to developing a complete model of the Galactic magnetic field.

25.10.2021 - 19:18 [ Dunlap Institute for Astronomy & Astrophysics, University of Toronto ]

Dunlap Astronomer discovers we may be surrounded by tunnel-like structure

(Oct.14, 2021)

Dr. Jennifer West, Research Associate at the Dunlap Institute for Astronomy and Astrophysics, is making a scientific case that two bright structures that are seen on opposite sides of the sky – previously considered to be separate – are actually connected and are made of rope-like filaments. This connection forms what looks like a tunnel around our solar system.

“If we were to look up in the sky,” explains West, “we would see this tunnel-like structure in just about every direction we looked – that is, if we had eyes that could see radio light.”

25.10.2021 - 19:10 [ SciTechdaily.com ]

A Vast “Magnetic Tunnel” May Surround Earth and Our Entire Solar System

(today)

An expert in magnetism in galaxies and the interstellar medium, West looks forward to the more possible discoveries connected to this research.

“Magnetic fields don’t exist in isolation,” she says. “They all must to connect to each other. So, a next step is to better understand how this local magnetic field connects both to the larger-scale galactic magnetic field, and also to the smaller scale magnetic fields of our sun and Earth.”

10.08.2021 - 12:48 [ National Aeronautics and Space Administration ]

NASA Team Studies Middle-aged Sun by Tracking Motion of Mercury

(18.01.2018)

Like the waistband of a couch potato in midlife, the orbits of planets in our solar system are expanding. It happens because the Sun’s gravitational grip gradually weakens as our star ages and loses mass.

10.08.2021 - 12:44 [ Forbes ]

Earth Is Drifting Away From The Sun, And So Are All The Planets

(Jan 3, 2019)

Deep inside the Sun, the process of nuclear fusion occurs. Every second, the Sun emits some 3.846 × 1026 joules of energy, which are released via the conversion of mass into energy in the core. Einstein‘s E = mc2 is the root cause, nuclear fusion is the process, and the continuous emission of energy from the Sun is the result. This energy is the underlying process that powers practically every biologically interesting process occurring on Earth.

15.07.2021 - 08:10 [ NationalGeographic.com ]

Surprise: Solar System „Force Field“ Shrinks Fast

(October 1, 2010)

It‘s cold, dusty, and bereft of planets, but the outskirts of our solar system are anything but dull, according to increasing evidence from NASA‘s Interstellar Boundary Explorer (IBEX) craft.

As charged particles flow out from the sun, they eventually bump up against interstellar medium—the relatively empty areas between stars. These interactions „inflate“ a protective bubble that shields Earth and the entire solar system from potentially harmful cosmic rays (solar system pictures).

15.07.2021 - 08:01 [ Massachusetts Institute of Technology (MIT) ]

The solar wind bubble that protects Earth has been mapped for the first time

Using data IBEX collected on ENAs as it charted just one 11-year solar cycle, the time between shifts in the sun’s magnetic field, researchers built a three-dimensional map of the entire heliosphere, which Reisenfeld says shields Earth and other planets from harmful radiation.

“Our Earth gets bombarded by cosmic rays, galactic cosmic rays all the time,” he says. These rays can subtly affect airplanes that fly near the poles, often on trips between Europe or Asia and the US.

Scientists say that to study other planet’s astrospheres, which is what heliospheres are called when they surround other stars, we must first understand our own.

21.02.2021 - 03:32 [ NASA.gov ]

NASA Missions Make Unprecedented Map of Sun’s Magnetic Field

They’ll have a chance to take that step forward soon: A re-flight of the mission was just greenlit by NASA. Though the launch date isn’t yet set, the team plans to use the same instrument but with a new technique to measure a much broader swath of the Sun.

“Instead of just measuring the magnetic fields along the very narrow strip, we want to scan it across the target and make a two-dimensional map,” McKenzie said.